Copper-tungsten/copper-alloy integrated contact and preparation method thereof

Abstract

The invention relates to a contact material for high-voltage switches and discloses a copper-tungsten / copper-alloy integrated contact and a preparation method thereof. The copper-tungsten / copper-alloy integrated contact comprises a contact part and a conducting rod part, wherein the tungsten content of the contact part gradually decreases from head to tail. The preparation method comprises the following steps: firstly, mechanically mixing powder by a wet method to prepare copper-tungsten particles with different tungsten contents; secondly, putting the tungsten in the die cavity of a compression mold according to the weight contents of tungsten in a descending order to carry out the press forming; thirdly, putting the pressed blank in a graphite boat, and sintering and infiltrating the pressed blank in a sintering furnace in the hydrogen atmosphere to obtain the copper-tungsten alloy of the contact part; and finally, sintering the low-tungsten-content end of the copper-tungsten alloy and the copper conducting rod part or the copper alloy conducting rod part to form an integral body by using a sintering method, an electro-beam welding method or a diffusion welding method, thereby obtaining the copper-tungsten / copper-alloy integrated contact.

Description

technical field [0001] The invention relates to a contact material for a high-voltage switch, in particular to a copper tungsten / copper alloy integral contact and a preparation method thereof. The contact is suitable for a high-voltage switch and a circuit breaker. Background technique [0002] Copper tungsten contact materials are widely used in various circuit breakers, vacuum load switches and transformer transfer switches because of their good arc erosion resistance, welding resistance and high strength, especially copper tungsten / Copper alloy integral contact material is the most widely used. [0003] The contact part of the copper-tungsten / copper alloy integral contact is copper-tungsten alloy, and the conductive rod part is copper or other copper alloy. However, with the increase of the voltage level of high-voltage switches, the requirements for the properties of the contact materials are becoming increasingly stringent, especially for high-voltage electrical appli...

AI Technical Summary

Problems solved by technology

However, with the increase of the voltage level of high-voltage switches, the requirements for the properties of the contact materials are becoming increasingly stringent, especially for high-voltage electrical appliances above 550Kv, the contacts are required not only to have high ablation resistance, but also to have High thermal conductivity, to quickly dissipate the large amount of heat generated during the breaking process, to prevent the formation of high thermal stress concentration at the interface between the copper-tungsten alloy and the conductive rod, which will cause the copper-tungsten alloy to fall off, thereby reducing the operating reliability of the switch. This requires copper-tungsten / copper alloy integral contacts to have high bonding strength at the same time

[0004] At present, in the copper-tungsten alloy integral contacts produced by high-voltage switch contact manufacturers, the copper-tungsten alloy part has a uniform composition. This copper-tungsten\copper alloy integral contact has a sudden change in composition, which cannot be transferred quickly during the switch breaking process. The heat generated by the arc forms thermal stress. The higher the voltage level, the greater the thermal stress generated. The stress concentration at the abrupt interface will cause the copper-tungsten alloy to partly fall off, which cannot meet the requirements of high-voltage switches.